


Undercover

by funesgol



Category: Chicago Fire, Chicago Med, Chicago PD (TV)
Genre: F/M, Sex, Sister - Freeform, Smut
Language: English
Status: In-Progress
Published: 2020-04-23
Updated: 2020-04-23
Packaged: 2021-03-01 17:22:40
Rating: Teen And Up Audiences
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 2
Words: 2,958
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23800753
Author URL: https://archiveofourown.org/users/funesgol/pseuds/funesgol
Summary: Y/N is Adam Ruzek's sister but she is also very good at being undercover. Her aptitudes are very good for a cop, except she isn’t one. One night she chooses the wrong target and everything starts to go wrong.
Relationships: Will Halstead/Original Female Character, Will Halstead/Reader, Will Halstead/You
Kudos: 14





	1. Part 1

**Author's Note:**

> This story was also uploaded on Tumblr.

**Part 1**

The woman started walking to the bar. The stilettos resonated with every step she took. She took one look until she found a target. Bingo.

A tall man, he had a suit that looked expensive and was taking a long drink. She could smell the dollars from a distance. She came over and sat down on the bench next to him.

Her butt, tight in that little red dress, looked bigger than ever. She took advantage of that and sat down in the middle of the seat to make it look even more voluptuous.

“A martini, please" she muttered to the barman. She stretched out on the table to order and of course, he looked just where she wanted him to.

“I invite you" a male voice appeared. She turned around and looked at him from top to bottom. “And get one for me too.”  
“Do you think you'll get my attention that easily?" she said in a British accent, making things more difficult. She knew what she was doing, it wasn't the first time. Men like him liked to play before they got to second base.

“Haven't you been watching me since you arrived?” The man raised an eyebrow, looking ironic. Y/N didn't like what she had heard. She had been looking at him longer than she should have, and of course, he noticed.

“Do you want the truth?" She said, in the sexiest voice he'd ever heard. She played with his long blond hair a little. “I had never been with a redheaded man before.”

He laughed. He put his tongue to his lips to soak them. She knew what he was doing. He was stalling because he didn't know what to say. Touché.

“Welcome to America, miss, the land of opportunity.”

The martinis came and both of them approached. Y/N was taking the bait, just like she wanted.

“And what's your story?” He asked, "Are you on vacation here?”

She took a little sip and nodded. “I'm here for work. I arrived just today.”

“And did you like what you saw so far?”

She looked him in the eyes and gave him a captivating look. “I like it very much, yes.”

It took a couple more drinks to make things more comfortable. The guy said they could go to his house. Y/N was a little sorry for him. The truth was she was liking him. Under different conditions, she would have liked to have done things right. When he parked the car, the girl took her time to inspect the place, before getting out. She was grateful there were no security cameras anywhere on the block. As soon as she crossed the threshold of his door, she knew she hadn't made a mistake.

He was a surgeon at Chicago Med. He probably had everything she had come for. The woman took off her coat as she watched him. He was putting the personal items he had taken out of his pockets on a small table by the door. Keys, cell phone, wallet. “Will you have a drink?”

She smiled at him. “Don't you think we've had enough to drink?” The young woman was on the sofa, her legs were crossed, one on top of the other. She wasn't stupid. She knew her dress had been lifted. And she knew that was all he was looking at.

“Yes, I think you're right. I'm sorry.” He pounced on her. She immediately felt the couch sink under her. The man's hands caressed her entire body over her dress as both mouths melted into a passionate kiss. They seemed to be struggling to breathe but neither wanted to break the bond anyway. She pulled the buttons on his shirt to pull it out. She was the one who took the initiative, of course. She took his belt with one hand and unbuckled it, while with the other she unzipped his pants.

“Hey, hey, wait” the doctor stepped back. He looked into her eyes in the darkness, illuminated only by a lamp “I don't even know your name.”

“I don't know yours either” she decided to take the lead in the situation and made him fall on the couch beside her. She ran both legs over his. She started kissing his neck.

“My name is Will” he said. “And yours?”

“You can call me Agatha Christie, Will.” He began to laugh at her comment and let himself be kissed by her. He unzipped her dress and gently stroked her back.

“Are you going to let me finish what I started or are you suddenly part of the CIA, Will?” He nodded, no longer paying much attention. He just let himself go. And so he kept doing it. “Yeah, I thought so” Y/N continued her work by starting to leave a path of kisses from his neckk, through his chest, his biceps, his stomach... all the way down. “Oh, wait” she stopped. “If we're gonna do this, we need protection.”

“Oh, yeah. I got one in-”

“Don't worry?” she said, smiling “I got it. I'll get my bag, I'll be right back.” She kissed him one last time and walked to her purse. It was small enough to carry everything she needed. That meant a gun and a syringe. Usually, she didn't use the gun (although she didn't hesitate if the time came) but she did use the syringe, without fail. She filled it, in the middle of the darkness, trying to do it quickly so as not to arouse suspicion.

Seven milligrams of midazolam. Perfect.

She hid the needle in her hand, drawing his attention as she approached so the man would not notice. “Did you find it?” He asked as she approached. “Of course I did.”

She climbed onto his legs, once more, and pulled his hair. He groaned, making her feel things. Things she never felt when she was doing her business. But Y/N didn't have time to think about it now. She stuck the tip of the needle in the man's back and injected the liquid into him. She continued to kiss him for at least forty more seconds until she realized he was already asleep. She separated from him.

“I'm sorry, Will, you were really cute.” Y/N don't know about sentimental. She didn't have any time to waste. She went up and down the house looking for money. She found some cash, she was sure it wasn't much for him, but for her, every penny counted. She took one last look at him, grabbed her shoes and her wallet.

She dressed presentably once more so she could get the hell out of there. Once she got to the door she took his wallet. She took all the credit cards he had. She felt something in his stomach as soon as she saw his ID photo. But it couldn't be guilt. Y/N L/N didn't feel guilt, ever.

“I’m really sorry," she whispered as she put away what she had found in her purse and bra, even though she knew he couldn't hear her.


	2. Part 2

**Part 2**

The Chicago police intelligence unit used to catch every criminal that it set out to catch. The other officers thought it was easy, but they never saw the work before the arrest. Searching for information, gathering facts, talking to informants. None of the superiors took into consideration their hard work, which was not done alone. Each and every one of the detectives in charge of Sergeant Voight put in their greatest effort to make the teamwork pay off.

But on this particular day, Detective Jay Halstead could not concentrate. His phone kept vibrating in his pants pocket, and that was something everyone had noticed.

“Halstead, are you with us?” Voight's gaze settled on him.

“Of course, sergeant.”

“Well, tell that to your cell phone.”

The boy's face turned red instantly because of the embarrassment he felt about being exposed by the boss, in front of all his buddies. He took out his smartphone and hid it under his desk, ready to kill the one who kept calling.

He was surprised to see that it was his brother Will.

«Stop bothering» He wrote the text as fast as he could and sent it. He immediately got a response.

«We need to talk. NOW. »

Millions of ideas crossed his mind about what might be happening and none of them was good. It could be his father. Will wouldn't bother him if it wasn't something important. He knew very well that he was at his workplace.

His thoughts must have been transferred to his face because when he raised his head, everyone, in the room was looking at him.

“Jay, do you need to go outside?” This time Voight wasn't being ironic, he was being supportive. The ex-soldier nodded to go somewhere away from the rest. "Thank you, sergeant" he said.

Once alone, he started calling.

“Will” his voice came out like a sigh as soon as his brother answered the call, "What happened? Are you okay?”

“I don't know" he answered. Jay didn't know how to interpret his tone of voice. “I'm so angry, how could I be so stupid!”

“Wait, wait” he tried to calm him down. “What are you talking about?”

The man on the other end of the line kept yelling things the detective couldn't understand. He asked him to calm down, one more time. “I have to tell you everything.”

“It's all right.”

“I've been robbed” there was a deep silence on the call. “Not on the street, not in the hospital. In my house. By a girl I met in a club.”

Jay rolled his eyes. “I really can't believe you called me to talk about this. Report the lost property and get over it. It'll give you experience.”

“You don't get it. It wasn't just a robbery. It was all planned, Jay. She injected me with some kind of substance to put me to sleep. Believe me, I know what I'm talking about. She's turned the whole department upside down.”

The detective didn't even let him finish. “It's okay. We're working on a case now but when you finish your shift at the hospital come down to the station so we can try to reconstruct his face and get an arrest warrant. Are you happy with that?”

“I don't know” Will finished the call and of course he wasn't happy with his brother's response. Meanwhile, he went back to Voight and the rest of the team.

[x]

Erin Lindsey was standing in front of the board. The images that were on it had been taped there a few minutes ago. “Julio Mamani. He belongs to the _Latin Gods_. We've seen him and his people before, but they had always gone unnoticed. They've cooperated with the police a few times.” She said, pointing to the man in the first photo.

She stepped forward and pointed to the next photo. “Andrés Rivera. He has worked with the Latin Gods, but he separated from them in 2016. Our informants say Mamani and Rivera had fought and Mamani forced him out of Chicago. But one of Antonio's informants claims she's seen him come back.”

“Do you trust her, Antonio?” Hank asked the dark-haired detective.

He nodded. “She's never lied to me. Her information has always been true.”

“The question is, why is Rivera back right now?” continued Erin, trying to develop the information as clearly as possible. “If he left almost without a fight before, what's so important that he came back to face Mamani?”

Adam Ruzek stepped forward so that he could ask. “And why do we think Rivera came back for Mamani? I mean, maybe he forgot something the last time he was in Chicago.”

“We know from this” She pointed to a picture with very low quality. The first thing you saw at first glance was the pixels. You could see that it was a cargo truck. The second thing you could see was the kilos of cocaine that the members of Latin Gods were taking out of the truck. “This image was obtained by Mouse from the security camera of a nearby pharmacy. All this cocaine, we could count at least 20 kilos, belonged to Rivera. He's been smuggling it into Chicago's Mamani areas for at least three years.”

“We think Rivera's back to take down Mamani” Antonio stood up and joined Erin. “We're not sure, as I said, it's a theory.”

Olinsky, from his hidden desk, made an important point. “And if Rivera ends up with Mamani, a gang fight will break out.”

“Exactly” Erin finished. “And we can't let that happen.”

Hank Voight nodded. He stood up, ready to give the orders.

“Halstead and Lindsay, find out everything you can about Rivera. I want to know every step he's taken in the last four years” the sergeant pointed them out. Then he turned to Ruzek and Atwater. “You two concentrate on Mamani. Find out about the places he usually hangs out. If Rivera goes looking for him, he'll probably do the same. Al, come with me.”

[x]

Sergeant Platt appeared in the room accompanied by a red-haired man. He was wearing medical clothing and his face was unsettled.

“Halstead, your brother is here," said the woman, then she turned and walked out.

“Yes, thank you, sergeant.”

Will Halstead joined his brother. He welcomed him with a smile, mocking him. “So... How are you?”

“Stop mocking me, Jay. I'm telling you, I'm serious. “

They weren't alone in the room. Erin Lindsey and Kevin Atwater were with the brothers. They both said hello, curious to know what was going on. It was the woman who asked first. Jay went ahead and answered.

“My brother had a problem with a girl.”

“It wasn't a problem!”

“Atwater, how many girls you meet in bars do you take home?”

He didn't want to answer, but he didn't have time because Will beat him to it.

“I met this girl at a club, we had a couple of drinks and went to my apartment. I woke up today with the whole place a mess and no credit cards. I took a blood test” he pulled a folded sheet of paper out of his pocket. “She injected me with midazolam.”

“That's what you get for wanting to take every woman you see to the bed” he went back to bother him. “Kevin, could you help us make a portrait of her?”

Atwater nodded and got on with it. Erin took her notebook. “Tell us everything you remember about her.”

“She was blonde, long hair, brown eyes. She must have been in her twenties, twenty-two. She was British. She said she arrived in Chicago just yesterday.”

The woman was writing while the man was drawing on the tablet. Jay looked at him to ask him a question. “Did she tell you her name? Anything about where she was staying?”

Will snorted. He put his hands to his head, slowly denying. “She told me to call her «Agatha Christie» ”

Then Jay and Kevin broke up in a fit of laughter. So much that Atwater had to put the tablet down to keep it from slipping out of his hands. Lindsey didn't copy them, though. “Come on, Erin. Don't pretend you're not amused.”

“I am not really," she said, rereading her notes over and over again. “She just got to Chicago and the first thing she does is go to a club and make out with a guy?”

“That may not be your type, Erin, but hers is.”

The woman bit her lower lip. She shook her head. “No, all of this is odd to me.”

Atwater got in the way. “What do you think? Looked like her?” He showed him what the picture looked like. Will pointed out a couple of details and after the corrections, the man was sure of the picture.

“Yes, it looks like her” he suddenly seemed to remember something. He put his hand in one pocket and tried to find something, but without success, and then he went back to the other one.

Ruzek entered the room. He had a folder full of papers and looked ecstatic. “Hey, you won't believe what Mouse and I... Oh, hi, Will!” He walked over to the others and handed out different papers to the three detectives. “Well, what Mouse and I discovered. Every Friday night Mamani and a good number of the Latin Gods go to the West Meigs Casino. Apparently, they frequent certain prostitutes, one of whom is an informant for Antonio, which would serve as a starting point for us to go undercover.”

“Great job, Ruzek” Kevin congratulated him.

“Wait, I haven't said the hard part yet. Mamani will be in a special room at the casino. The police could ask for a warrant, but, obviously, the Latin Gods wouldn't go if we did that. So, Mouse is trying to get away in and-What… How…Where did you get that, Will?”

Ruzek pointed to his right hand. The surgeon raised it in the air, showing what was in it.

“The girl left it at my house. She probably dropped it while she was putting away the money she stole from me.”

“What are you talking about?” He said, but then he left his question behind. “You know what, never mind. That's a ticket to Room 11! Where Mamani will be!” the excitement was in the man's voice. “I have no idea how you got it, but now we just have to make enough copies. I'll go tell Mouse to do it. You're a genius, Will!”

Erin took one look at Jay. “You still think she had nothing to do with it?”


End file.
